This invention relates generally to surgical instruments and techniques and more particularly to instruments and techniques used in the removal of tissue and fat from a patient.
In the area of cosmetic or aesthetic surgery, body contouring is accomplished through a variety of ways including liposuction in which body fat and tissue are removed through the use of high vacuum pressure.
One of the earliest discussions of liposuction was made by Dr. Y. G. Illouz in 1983 (Illouz, Y. G., "Body Contouring by Lipolysis: A 5-Year Experience with over 3000 cases", Plast. Reconstr. Surg. 72; 591, 1983) in which some three thousand cases were discussed. This technique has changed little over the years and is commonly referred to as the "wet" method. A mixture of isotonic saline and epinephrine or vasopressin is used in differing dilutions. A general aesthetic is given. Using tunnels or strokes, the mixture is inserted into the patient in the area of interest. Using any of a wide range of cannulas, the tissue or fat is then withdrawn.
The withdrawal of the fat is usually accomplished through one of two methods.
In the first method, a cannula is affixed to end of a large syringe. The cannula is inserted into the patient such that the tip of cannula is in the area of interest and the surgeon creates a suction by withdrawing the plunger of the syringe. When the syringe is filled, the cannula is withdrawn from the patient and the contents of the syringe are discharged into a receptacle. The surgeon continues with this procedure (aspiration/discharge/aspiration/discharge/ . . . ) until the desired contouring is accomplished.
In this method though, because of the syringe's own capacity limitations, the process requires the repeatedly re-entry until the proper amount of tissue and fat is removed. Enlargement of the syringe to accommodate more volume is not feasible because, even at the present size, the syringe is so large and bulky that it is difficult for the surgeon to properly manipulate the end of the cannula.
Further, cosmetic surgery surgeons are quickly recognizing that a body's own fat may be used elsewhere on the body to provide contouring there. One such location where body fat has been used is near the corrugator supercilia muscle to correct for age lines in the face.
Because the fat/tissue aspirated by the syringe is discharged in an air environment, there is a danger that it can become contaminated making it unsuitable for re-injection into the body. The mere exposure of fat to air changes its physical characteristics making it less suitable for other body contouring applications.
In the second method, a suction pump is used to withdraw the fat/tissue. Again a cannula is used to direct the point of vacuum to a desired location. The fat/tissue is pumped from the patient using a conventional surgical pump. The aspirated materials pass through the pump and then into a repository.
Because of the intermediate step of the pump, and contacts therewith, the fat so collected is still suspect of contamination and is used only in extreme cases.
Additionally, because the cannula picks up air either due to gas entering the body cavity or during withdrawal of the cannula from the body, the suction force varies dramatically as the pump deals with the highly compressible air. This makes it more difficult for the surgeon to obtain consistent results.
Probably the most persuasive problems associated with either method is the excessive bleeding associated with the procedure and aesthetic sequelae (Erik Dillerud, "Suction Lipoplasty: A Report on Complications, Undesired Results, and Patient Satisfaction Based on 3511 Procedures", Plast. Reconstr. Surg., 88, 239, 1991).
It is quite common to withdraw as much blood as fat/tissue. This dramatic withdrawal of blood is not critical where a low amount of fat is removed, but, when a larger volume of fat/tissue is needed to be removed, complications result and recuperation time is extended and in almost all situations, supplemental blood is added to the patient, posing other dangers.
The aesthetic sequelae which has been experienced encompasses those well known with other types of surgery including: cardiac arrest, anaphylactic reaction, and respiratory arrest.
To increase the safety of the procedure, Klein has introduced the use of tumescent techniques using a local anesthesia (Klein, J. A., "Tumescent Technique for Local Anesthesia Improves Safety in Large-Volume Liposuction", Plast. Reconstr. Surg., 92, 1085, 1993). The tumescent technique involves the infiltration of a solution of lidocaine, epinephrine, sodium bicarbonate, and triamcinolone into the subcutaneous fat. Infusion is made through the use of a peristaltic pump. The tumescent solution reduces bleeding and eliminates the need for general anesthetics. The actual liposuction was conducted in the same manner as discussed before and hence had all of the limitations associated therewith.
Perhaps the largest problem associated with any of these methods is the risk to the health-care worker from aerial contamination and from the required multiple handling of the syringe. The syringe is passed from one party to another for aspiration of the fat from the patient, to expulsion into a container, and back for aspiration. This handling increases the potential of a puncture to one of the health care worker.
Additionally, in all of these procedures, a team is required for the surgery. This team must work together in withdrawing the fat and the handling of the instruments. As more people enter into the operation, the time required for the operation .increases resulting in more trauma to the patient.
It is clear that the lipoplastic procedures and equipment of the current art creates certain dangers to the patient, and inhibits the surgeon's ability to perform the operation. Improvement of these procedures and equipment is needed.